Self-developing photographic surface.



Patented Apr. 6, 1909.

W. F. C. KELLY L J. A. BENTHAM.

SELF DEVELOPING PHOTOGRAPHIG SURFACE. APPLICATION FILED APR.23,1906.

* TED STATES PATENT OFFICE.

WILLIAM FRASER CLAUGHTON KELLY AND J OHN lARTHUR BEN THAM, OF LONDON, ENGLN D.

'SELF-DEVELOPZING PHOTOGRAPHIE SU'RFACE Patented April 6, 1909.

appiication mea April 2s, isos. semi No. simio.

" To all-whomit. 'may concern:

Bc it known that we, WiLLiAiifItAsER OLAUGHTON KELLY, bari-ister-at-law, and JOHN ARTHUR BEN'rimiii, gentleman, subjects of the King of Great Britain, residing, respectively, at 8-Ierha1'ii road, lensincfton, an( 36 Beaumont street, Portland Pd both in the county of London,`England, have invented certain new. and useful liuprovevments' in Self-Devolo ing Photographic Surlaces, of which the ollowing is aspeciiication. Our invention relates to an improved method of developing lphotographic plates, iiliiis, bromid paper or the like, and the adaptation of the plates oriilms to this method of development.

Ouil plates or iilms are so pre ared that mere immersion in water effects t eir development as they carry on the back thc essential constituents of the developer in a dry state.

We are aware that photographic surfaces bearing their own developer in a dry state, have already been pre ared, as inventions having thisaim go bac to 1887; and as an example of such an invention applied to dry plates we may refer to Backslandt sinvention as disclosed in the specification of his British Letters PatentNo. 1201 A. D. 1888 and we therefore make no claim for that special fea ture. We are also aware that Thornton and others in their specification No. 17-292 A. D. 1899 made certain proposals, but these were impossible in iractice as the developing composition could not keep.

According to the present invention, we prepare a concentrated developing mixture in a thick or semi-fluid condition, and conl back of the plate, film or the like.

' borax 10-20 grains, gum .or other 'suitabletaining as a preservative and alkaline constituent borax, boracic acid or a soluble borate, and this mixture we spread on the We allow the developing compsition to dry, and if, after suoli a plate or iilin has been exposed in the camera, it is immersed in water, the water will dissolve the backing and so become itself a developing iluid.

The following mixture for backing is, convenientfor use, but we do not bind ourselves to this special composition, as it is Well known that developers must be varied to suit laes and conditions z-Metol 2 grains, hyroquinone 5 grains, metabisulte of potas-` sium -lgrai, bromid of potassium grain,-

ace,

colloid i grain,water suilicient to make a thin paste. These materials are ground together, applied to allowed to dry. The quantity stated above is sullicient for a quarterv late. l

In 'the accompanying i'awingsz--Figures 1 to 5 show the manner of laying or arranging the developer on the back of the lni oi'plate.l Fig. lis a lan view of one embodiment of the invention; Fig. 2 is an edge view; Fig. 3 is a plan view of another the back ofthe plate, and

embodiment of the invention; Fig. 4 is a plan view of a further embodiment; and Fig. 5 is a sectional view of a still further embodiment.

' As shown in Figs. 1 and 2, A represents a,

glass or other plate and B thedeveloping paste, spread on the back thereof. 1When the composition is to be applied to the back of a roll film it is necessary to so adjust the constituents as to secure liexibility. We quadruple the above quantities (except the gum) and mix the ingredients with fifty drops ofgu'm arabic mucilage, four drops of glycerin or syrupy glucose and. sufiicient water. This quantity of mixture will serve for coating the back of an Ordinar six ex- 'osure quarterlate roll ilni. nstead'of incorporating al mixture we sometimes keep separate the reducing and alkaline constituents, and spreadthesev on adjacent areas on the back of the plate, film or the like.

Our composition as given above may be divided into two or more constituents as followsz-The two grains metol vand the five grains hydroquinone and the metabisulte of potassium may be mixed with alittle gum,V

and spread on a portion of the plate as shown at B in Fig. 3. The borax, or accelerator, similarly treated and applied is shown by B2, and the bromid, naturall space, may be placed as at 3lfrom whence it can be removed by scraping or sponging be# fore development, should this course be deemed desirable. Similarly, the other con stitu-ents maybe adjusted or proportioned by the o erator. A thin coating or washof gum ara ic or sugar in solution, or a mixture of both is a protection which we apply over the developing composition when exposure to trying atmospheric' conditionsv is anticipate When We deal with roll films and divide the developer into constituent parts as above described, it is often convenient to ar'- the constituents of the occupying less i range the constituents on sequent exposuresections of the roll film" as shown in Fi 4.` A. being the iilm or su port, B B, B the constituents of the deve oper.

In order to avoid excessive reiiection of light from the back through the plate in the" case of the single composition, and any un-vl l equal reection'in the case of the` developerv cases the lig vbetween the sensitive lcomposition or a constituent of it.

in separate constituents we interpose a light absortive layer between the support and materials; but in certain t-absor tive layer maybe m andA the support, but We make .no claim to the combination of sensitive absor tive layerand sup ort as same forms the su ject of Oakleys British Patent No. 2986 of 1895. Fig. 5 shows the lastV mentioned arrangement. C being the plate or support. D the dry devellgpiplg t e the s evelopin light absortive layer, E the sensitive stral a vehicle for the color.

40 dyejwe may use lampblack or other suitable.

`5 rains.

he solution is appliedto the support and dried before coating with sensitive emulsion.

Sometimes We prefer collodion or the like as For coating the back of the plate We ma use a similar composition or 1n place of t e crocin scarlet or other 7 ven our developing com osition forms one unbroken coverm plate or as showny y Fig. l. B, it is convenient. to incorporate the light-absorptive material with the developing constituents, in t case We may add l /10 grain crocin or lamp-black or other suitable dye or` igment to the developing mixture. descr?. ed above. n

ln order to carry out ouir invention as applied to roll iilm with certainty oi success over t e back of the einem under all climatic conditions it is'necessary to interpose an impervious mediumbetween i y the convolutions ofthe i'ilm, otherwise the developing composition might act onV the sensitive stratum. The black. needle paer ordinarily used to protect roll lm rom light is seldom or never sufficiently impervious to chemical action-but We render it sufficiently im ervious by drawing it throu h a celluloi varnish or the like. 0n

g band of celluloid, waxed paper, Macintosh cloth, foil or the like.

the lot er hand .we sometimes use a protectf What we claim and desire to secure byLetters Patent of the UnitedStates is 1'. The combination with the support for the sensitive layer, of a developing composition applied to the back of the support and .mixed with a light-obstructin material.

2. The combination with t e support forthe sensitive layer, of a developing -composi' tion-applied to the back of the sup ort and mixed with a material imparting exibility to the composition. f

3. The combination with the support for the sensitive layer, of a developing composition applied to the back of the support and mixed with a li ht-obstructing material and with'a materia imparting flexibility `to the composition.

4. In self develop' g photographic plates "or lms the combination of a light-obstructing material With the developing and preserving constituents lupon the back of the plateor film, substantially as described and or the puipose set forth.

5. In se developing roll iilms the combi- 'nationwith the developing compositions spread on the back of the lm of a material imnarting ilexibilit thereto..

testimony W ereof we have hereunto set our hands m resence of two subscribin witnesses this 11t day of April' 1906.

WILLIAM Frases cLAUeHro, KELLY. Y JOHN ARTHUR Barnim.

` Witnesses so far as regards W. F. C.' Kelly: H. D. JAMEsoN, i l l A. N UTTING.

Witnesses so far as regarded; A, Benthem:

WM. Pinnen, I H. Watson. 

